Harvest Ready

Fine-tune your combine to put more corn in the hopper

There is easy money to be had in your fields this fall. We’re talking three or four $5 bills sprinkled across each acre of corn, just waiting to be picked up. On 1,000 acres, that adds up to at least $1,500. All you have to do to pocket the additional cash is spend a few hours fine-tuning your combine prior to harvest. When was the last time you spent half a day on anything and made a $1,500 return on investment?

Here’s how you know that money is sitting out there in the field, like low-hanging fruit: One full 3⁄4 lb. ear of corn every 1⁄100th acre equals 1 bu.-per-acre yield loss. In 30" rows, 1⁄100th acre is 174'. If you walk around a 174' area and see enough partial ears and kernels to form one full ear, that’s a lost bushel of corn.

In most fields, there are several lost ears of corn per acre to be had, explains Brad Beutke, who spoke on the topic at the Farm Journal Corn College Advanced events in Illinois. On average, corn growers lose 3% to 5% of their yields each year because they don’t prep their combine, he adds.

In the next six steps, Beutke details how to use management practices and pre-harvest adjustments to improve combine performance, recapture losses and put more corn in the hopper.

1 Review your manufacturer owner’s manual. It’s old news, but still true: the best way to acquaint yourself with your combine is to read through the owner’s manual. Many of the adjustments you need to make are addressed in simple language and easy-to-understand diagrams. Unfortunately, few farmers pay attention to their owner’s manual, so do yourself a favor and look it over before you roll into a field.

2 Focus most of your attention on the header. Header loss accounts for up to 90% of total harvest losses, Beutke reports. Farmers are increasing the size of their combines but not pairing it with an appropriately sized header. Farmers often overdrive the header, which increases ear and kernel losses. The stalk rolls are the portion of the header that needs to be sped up in order to increase groundspeed. On most heads, the entire header has be sped up to accomplish this.

"A lot of farmers want to use an eight-row header because it’s easier to get up and down the road and move around, but they want a machine with more capacity to go with it," Beutke notes. "The problem is they end up driving faster, and the faster they drive, the more ear and kernel loss go up."

In the process of making the header run faster than it’s designed, sometimes other components in the head, such as the gathering chains or the cross auger, move too fast. As a result, you can get more grain damage or even flip ears out of the header. Beutke says there are aftermarket components that allow you to slow down other portions of the header in order to do a good job at the faster ground speeds farmers are running today.

3 Level the combine concave to the rotor or cylinder. In your owner’s manual, one of the first things you’ll read is that all manufacturers recommend leveling the concave to the rotor or the cylinder during pre-season maintenance. This makes sure all of the clearances in the threshing portion of the combine are zeroed out and that the concave isn’t too tight in the front rotor, which can cause grain damage. Likewise, a wider gap at the back will cause separation problems in the rear portion of the threshing system.

4 Determine the origin of your losses. It’s important to be able to measure the two different kinds of grain loss—ear and kernel loss—and to identify where those losses originate. Are they from the header, separation or cleaner portion of the machine, and how much of a loss do you see? The industry standard is 2% grain loss or less, which Beutke says is achievable, once the machine is set properly.

"The one trend I see is that farmers are concerned about the quality and worry about that more than actual loss, yet rarely do they get a premium for high-quality corn," he says. "No. 2 corn is allowed 5% total damage, and 3% of that can come from foreign material and broken corn, which your combine adjustments will help correct. In most cases, you’re better off to chase losses rather than to chase more quality."

Beutke recommends measuring pre-harvest losses before pulling your combine into the field. Look for ears on the ground to establish this. After you run the combine through the field, recount the number of ears on the ground. The difference between your pre-harvest loss and post-harvest loss is ear loss.

Kernel losses are bit tougher to calculate because you have to count the number of kernels on the ground.

Every two kernels per square foot are equal to a 1 bu.-per-acre loss.

"We like farmers to stay within a 2% yield loss or less," Beutke says. "That means, in 200-bu. corn, if you have zero ear loss, you don’t want to see more than four kernels per square foot."
What’s more important is to recognize where those kernels come from. For instance, if you’re checking header loss, check between the back of the header and the rear portion of the combine. Any kernels you find in that zone are just from the header.

Depending on the machine, it gets a bit tougher to tell the difference between separation loss and cleaning loss because of how the rear portion of the machine is set up. For example, if you have a chaff spreader and all of your excess cleaning material over your screens gets thrown on the chaff spreader, that residue might get spread across 50'. However, if you have that same machine without a chaff spreader, the residue might get spread over 6'. Depending on how your specific machine is set up and the header you use, you’ll need to make a number of calculations. Refer to your owner’s manual for details.

5 Minimize the number of tailings. Tailings are the material that makes it through the first set of screens but not the second set of sieves. That material goes through the elevator and then goes back through the threshing process a second time.

Beutke advises farmers to keep their tailings system running at 30% or less of its capacity. "If it’s higher than that, you tend to have more kernel damage and you’re giving up capacity," he says. "You have to strike a balance between keeping the capacity down, clean grain quality and minimizing losses."

On some of the newer machines, tailing processors are installed to increase machine capacity by rethreshing tailings in a dedicated threshing unit.

6 Manage residue. As farmers move to ever-larger machines, they run into several problems. For example, if you have a poor residue spreading pattern out the back of your combine that can create planting issues the following spring. You might also run into nitrogen issues due to the varying levels of carbon residue dispersed across the surface. Bottom line—you want that residue spread as evenly as possible.

Another issue on the bigger combines has to do with the axial rotors. Axial rotor machines are built with the rotor running parallel to the direction of travel, and the machine augers material straight through. In these machines, the rotor usually discharges the residue heavier on the right side than the left because of how it turns.

Newer machines are now coming equipped with adjustable residue deflectors behind the rotor to move the material from right to left as it enters the chopper. Retrofit kits can be found for some older machines.

Managing each of these six steps can help you capture the full harvest poten­tial from each acre of corn.